The invention uses various materials which are electrically either conductive, insulating or semiconducting, although the completed semiconductor circuit device itself is usually referred to as a "semiconductor". One of the materials used is silicon, which is used as either single crystal silicon or as polycrystalline silicon material, referred to as polysilicon or "poly" in this disclosure.
In the operation of certain semiconductor circuit devices, such as DRAMS, it is necessary to draw down the latch node (or the sense node) of the sense amp to a certain low potential, for example, a potential of V.sub.SS or V.sub.TN. The biasing of this node enables the sense amp to sense a differential in signals between signal sources, such as between digit and digit* lines. It is advantageous to very rapidly bring the potential of the node to the low value in order to reduce the time for the sense amp to detect the differential in signal levels of the digit and digit* lines.
In one prior art technique, the sense amp was strobed to a ground potential and the substrate was pumped to -2.5V with respect to ground. The pumping of V.sub.SS to -2.5V resulted in current consumption which would have been unnecessary if substrate was set to be equal to ground.
If the sense amp node were connected through a diode to ground, then the sense amp node would go in potential to a level of ground plus V.sub.T of the diode with the substrate grounded. This achieves the same effect as the case where the substrate is pumped to 2.5V. As the potential of the node approached ground plus V.sub.T, the change in potential would tend to slow, resulting in the potential of the node hyperbolically approaching ground plus V.sub.T . On the other hand, if the node was connected by a transistor to ground, then the potential of the node would rapidly drop past the desired ground plus V.sub.T and settle at ground potential. It would be desirable to have the potential of the node drop rapidly, as in the case of a transistor connection, but settle at a potential of ground plus V.sub.T.